Day 4:
“Let there be lights in the expanse of the heavens to separate the day from the night, and they shall serve as signs and for seasons, and for days and years;”
The separation of day from night happened in Day 1 but because the frame of reference or viewpoint is the surface of the earth, the reason for the cycle between light and darkness couldn’t be determined because the sun was not visible and the earth’s rotation. as a result of the collision with Theia, was not apparent from the earth’s surface. The atmosphere was still too dense. By Day 4 the atmosphere is now more transparent and the sun and moon are now visible for the first time, as are the stars. A common misconception is that they were created at that point. But that simply cannot be true because verse 18 (during Day 4) states very clearly it is the sun and moon that govern the day and night and separate light from darkness which happened during Day 1, as we have seen.
“God set them in the expanse of the sky to give light on the Earth, to govern the day and night, and to separate light from darkness.” Gen 1:18
To repeat, this verse confirms that the sun and moon were in existence by the end of day 1 when day and night was first established.
If the frame of reference was outer space, a God’s-eye view, then it would be a contradiction to suggest that sun and moon were created on Day 4 after there was ‘day and night’ at the end of Day 1. But the visibility of the sun and moon on Day 4 is consistent with the surface of the earth as the observation point.
Day 5:
“Let the water team with living creatures, and let birds fly above the earth across the expanse of the sky.”
Now that the ozone layer is protecting the earth from too much UV and the sun and moon are clearly seen, it enables birds to migrate and there is explosive speciation particularly of smaller animals initially but also large water creatures.
“God made the beasts of the Earth after their kind and the cattle after their kind”
We see the clear progression from small aquatic creatures to larger aquatic creatures and a whole range of terrestrial creatures small and large. The order follows the fossil record. Smaller aquatic creatures are the oldest recorded fossils and more complex animals are progressively layered.
It is important to note that the use of the Hebrew word ‘kind’ is ‘min’ and elsewhere in the Bible ‘min’ refers to species, not genus or phyla. Eg. Leviticus 11:22 lists locust, katydid, cricket, and grasshopper as separate ‘min’ and Deuteronomy 14:12-18 records eagle, falcon, hawk, red kite, black kite, vulture and black vulture as separate ‘min.’ Young Earth Creationists make the mistake of attributing ‘kind’ to genus.
Day 6:
“Let us make man in our image, accord to our likeness and let them rule over the fish of the sea and the birds of the air and over the cattle and all the earth.”
Creation of humans. Important to note that we are created uniquely in the image of God and all animals are under our authority. We are eternal, animals are not. Consequently, one human being is worth more in God’s sight than all the animals in the world. The way we treat our pets these days would indicate that we have forgotten that profound truth.
Day 7:
“He rested on the seventh day from all the work he had done”
After the creation of mankind, there have been no new species of any note. Just extinctions. We are currently living in the Day 7 era. From the fossil record over 100 million new species have been noted in these last 500 million years. God was ‘very busy’ creating these individual species to prepare the earth and atmosphere surrounding the earth so that the pinnacle of his creation, humans, could have the very best environment to not only survive but thrive. Many of these species served their purpose and were extinct long before mankind arrived. Since the advent of humans, there has been essentially no recorded speciation. Just progressive extinction of these remaining species. God has rested.